Problem/Motivation
By @finnsky in #3391723: [PLAN] Accessibility review:
We could add Nightwatch tests because we have automated Nightwatch a11y tests in core: #3293469: Automated A11y tests in Nightwatch. Added simple tests using it.
How to start with Nightwatch testing can be found in `core/tests/README.md` file from Drupal core.
This issue should be focused on implementing a first simple test, like "(If logo) it takes you to the homepage" and define the structure the rest of the tests will follow.